Ring-Gap

[quadman21]

I'm getting my clyinder honed today. I goofed before and left out my o-ring that goes around the sleeve at the base of the cylinder. So I'm just getting the hone and putting the same piston and rings back in. Should I be alright? shuold I be concerned with my ring-gap increasing?

[MIKE400EX]

They shouldn't have taken enough out by honing the cylinder to increase the end gap significantly. .001" removed from the cylinder (which would be a lot for honing) only increases the end gap about .003"). I wouldn't worry about it.

[quadman21]

Hey mike, while we are on the subject let me ask you a question. When I left that o-ring off I ran into some trouble. #1 when I start my engine the top end knocks for only a moment and immediatly goes away. As if it takes a moment for the oil to get to the top end. #2 I had a composite gasket and oil started leaking from it and of course, it started to smoke. from what I could see and after reading one of your replys, I can only guess oil made it's way between the sleeve and cylinder. Now that I am putting that o-ring back on those symptoms should stop right? I know I'm sounding vague, but I would appreciate your advice.

[MIKE400EX]

I'm assuming you do mean the o-ring around the bottom of the jug? That o-ring doesn't have anything to do with oil flow to the top end, and I don't think it has anything to do with your engine knock. How long does the knock actually last for, a few seconds, minutes? The head gasket, no matter what type, seals both the combustion gases and the oil pasageway between the jug and the head. When the head gasket was not sealing, and you were riding it, it's conceivable that some oil was leaking from there and getting burnt in the cylinder - hence the smoking. While you have it apart, have the cylinder checked for size, roundness and taper just to make sure that's not the cause of the smoking - will make your life easier later if you still have a problem. You can use the composite gasket type (a new one though) again, just remember you WILL have to re-torque it after a few engine running cycles. Also, as with any gasket, check to make sure the studs are not bottoming inside the cylinder nuts - if they/one do you'll won't get any gasket to hold. If Honda had just used open ended flange nuts on the cylinder head it would have saved a lot of people grief. Good Luck!

[quadman21]

The knock lasts for only seconds. When the oil leaked with the composite head gasket, it leaked on the side opposte of the oil passage. That's what had me confused. That's also why i thought the oil had found it's way between the sleeve and cylinder and was leaking into the combustion chamber. In any case, at that time i just wrote if off as a bad head gasket and replaced it. As soon as I took it apart you could smell the burned oil. So now I'm even more confused. I was thinking that if I just put that o-ring back in it would be ok. I have noticed that my sleeve has wear marks on the OUTSIDE in line with the stroke of the connecting rod. i.e. exhaust and intake. So now I'm just confusing myself as what to do fix it. My only two concerns are for it to stop knocking on start up and to not smoke.

[MIKE400EX]

Make sure that the sleeve is not loose. It should not move if tapped lightly on a wooden block. If it is then a little Loctite #660 will do the trick. It's not cheap but it works well, & be very careful to wipe any extra off. Also make sure the cylinder and sleeve surfaces are flat and flush to each other.

[quadman21]

If you mean flat and flush on top right, than i'm ok. The sleeve was a concern of mine because if in fact oil had pushed it's way up between it and the cylinder, than in theory the sleeve would have "floated" in the cylinder. I remember on another post you gave advice on "not to forget the o-ring". You further went on to explain that it prevented oil from doing precisely what I think mine did. but also it help keep some sort of bottom end pressure?
So if I put this o-ring on will it help push my oil to my top end quicker because the o-ring is not letting any oil pressure escape between the cylinder and sleeve? further more solving my few second knock? Or am I just stretching my imagination to make myself feel better?

[MIKE400EX]

Yes, flush on the top/head end. The o-ring doesn't put much pressure on the sleeve or cylinder, primarily just keeps the oil in check. Supply oil is only supposed to flow through the little passageway/hole that runs parallel to the cylinder, it passes through the base and head gaskets, not the o-ring, on it's way into the cam pocket on the righthand side of the head. Replacing the o-ring will not help getting to the top end. It's not a lack of oil, in the first few seconds, that's causing the knocking noise, because there's no hydraulic mechanism in the top end that reduces lash (like a hydraulic lifter in your car). There's not much in the top end that would heat up enough, in only a couple/few seconds, to take up "some" extra clearance. By a few seconds, are we talking about 2-3 or 20-30? Check to see that the cam is not moving/sliding back and forth. Is it a metallic kind of sound or a deeper tone? Does the sound go away if you only crank it over, not letting it fire (try it with and without a plug)? Also are there any spots on the bottom of the cylinder that look like the piston was scuffing at some time?